Spiderweb Agate AKA: "Crackle Agate" is a bold and unique stone with striking web like surface patterns. The patterns are most likely caused by a heat treatment that "shocks" the stone's surface into cracking. The stone has also undergone color treatment, which is quite common amongst Crackle Agates. These big bold stones are perfect for fun funky styles, and are certain to attract tons of attention and admiration!